Given a value for the in put variable x, and the output variable y, calculate the constant of proportionality. x = 21, y = 6. plz help

Which of the following statements is not true? a.parallel lines are lines in the same plane that never intersect. b.congruent figures have the same shape and same size angles and sides. c.similar figures must have the same shape and the same size. d.a rotation is when you turn a figure around a certain point.

Identify the expression equivalent to 4(x + x + 7) − 2x + 8 − 4 by substituting x = 1 and x = 2.

How can you find the magnitude of a vector, v = < x,y > , where the horizontal change is x and the vertical change is y?